Formulas for Better English
About Mr Boom.
The teacher behind
Mr Boom’s English Lab.
Welcome to Mr Boom’s English Lab! I’m Leslie Boom—an English teacher, Cambridge Exam Specialist, and digital educational publisher. I was born in England and later moved to Spain with my family, where I now run an English academy teaching English and preparing students for Cambridge exams from A2 to C2.
Living and teaching in Spain gives me a front-row seat to the exact challenges language learners face when aiming for exam fluency, and that experience shapes the practical resources I create.
Every resource in my lab—from complete speaking practice sets to vocabulary frameworks and assessment toolkits—is designed to save teachers hours of preparation time while giving candidates the structure they need to succeed.
Whether you are preparing for A2 Key or pushing toward C2 Proficiency, these materials deliver practical, exam-aligned practice that builds real speaking confidence.